VISCERAL PAIN IN ACUTE INFLAMMATORY CONDITIONS

A MODEL FOR PAIN IN INTERSTITIAL CYSTITIS / PAINFUL BLADDER SYNDROME
 

Referred mechanical pain in an acute cystitis model (Von Frey test).

Cyclophosphamide-induced cystitis is a well-characterized model of subacute, inflammatory visceral pain in rodents. This preclinical model is usually associated with urinary bladder inflammation, an increase in voiding frequency and a decrease in urine volume per void as well as an increase in painful behaviors.

Rat

• This is a new acute model of inflammatory visceral pain, characterized by an increase in pain response (mechanical hyperalgesia) and a decrease in pain threshold (mechanical allodynia).
• Compounds that produce positive effects in this model   include: non-steroidal anti-inflammatory drugs (aspirin and ibuprofen) and the opioid receptor agonist, morphine.

• The pelvic sensitivity to mechanical stimuli is assessed   using von Frey filaments of different forces, applied to the pelvic area.
• A series of mechanical stimulations are performed at different time points after intraperitoneal injection of cyclophosphamide in conscious animals.
• Compounds can be administered via various routes (i.v., i.p., s.c., p.o.).  

• Nociceptive threshold
• Percentage (%) of maximal nociceptive score
• Area under the curve (AUC) by plotting individual % of nociceptive score against von Frey force
• Others: inflammatory parameters, biomarker analysis

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